Multi-purpose derrick barge and method of use in oil well drilling and servicing



Sept. 26, 1961 J. E. LUCAS 3,0

MULTI-PURPOSE DERRICK BARGE AND METHOD OF USE IN OIL WELL DRILLING AND SERVICING Filed May 26, 1954 6 Sheets-Sheet 1 INVENTOR JOSEPH E. LucAs i j 7- 63 BY Zaao z nw ATTORNEYS Sept. 26, 1961 3,001,595

J. E. LUCAS MULTI-PURPOSE DERRICK BARGE AND METHOD OF USE IN OIL WELL DRILLING AND SERVICING 6 Sheets-Sheet 2 Filed May 26, 1954 INVENTOR J'osEPH E. LucAs BY I m l' ATTORNEYS Sept. 26, 1961 J. E. LUCAS 3,001,595

MULTI-PURPOSE DERRICK BARGE AND METHOD OF USE IN OIL WELL DRILLING AND SERVICING 6 Sheets-Sheet 3 Filed May 26. 1954 l I I 1 I lll l IIIL JosEPH E. LUCAS BY ATTORNEYS Sept. 26, 1961 J. E. LUCAS 3,001,595

MULTI-PURPOSE DERRICK BARGE AND METHOD OF USE IN on WELL DRILLING AND SERVICING 6 Sheets-Sheet 4 Filed May 26, 1954 lllll |..I llllllllL INVENTOR J'osEPH E. LUCAS ATTORNEYS Sept. 26, 1961 J. E. LUCAS 3,0

MULTI-PURPOSE DERRICK BARGE AND METHOD OF USE IN OIL WELL DRILLING AND SERVICING Filed May 26, 1954 6 Sheets-Sheet 5 J'osaPH E. LUCAS BY flue {M ATTORNEYS Sept. 26, 1961 J. E. LUCAS 3,001,595

MULTI-PURPOSE DERRICK BARGE AND METHOD OF USE IN OIL WELL DRILLING AND SERVICING 6 Sheets-Sheet 6 Filed May 26, 1954 JOSEPH E. LUCAS fiat-m ATTORNEYS Patented Sept. 26, 1961 3,001 595 MULTI-PURPOSE DERRICk BARGE AND METHOD IO$GUSE IN 011. WELL DRILLING AND SERVIC. Joseph E. Lucas, Caracas, Venezuela, assignor to De Long Corporation, New York, N.Y., a corporation of Dela- Ware Filed May 26, 1954, Ser. No. 432,543 24 Claims. (Cl. 1759) The present invention relates to well drilling and well servicing apparatus for use over-water. The invention also relates to a method of installing such apparatus at a well location.

More particularly, the invention relates to a combination derrick barge for platform erection, drilling and servicing under-water oil wells. The barge is constructed so that it can be raised above the water at a well site. A relatively small platform is erected over the water by equipment on the barge, preferably beyond one edge of the barge. This is accomplished through the use of a derrick boom mounted upon the barge. The platform is installed at a distance of at least twenty (20) feet from the barge. This space is spanned by a combination bridge structure and derrick floor. In case of fire, the barge can be quickly lowered onto the water and pulled away from the platform. The loss of the barge and other equipment is thus avoided.

Another feature of the invention is that, after a well has been drilled, all of the drilling equipment can be easily and quickly removed for use in drilling another well. This means that equipment representing little capital investment is left at each complete well site. On the other hand, if the well is not productive, the small platform and all other components can be quicklysalvaged for reuse at another site.

A further feature of the invention resides in the provision of a rotatable crane located approximately midway of the length of the barge. The crane is adapted to be converted into a drilling derrick by connecting the upper end of one or more rigid legs with the outer end of the crane boom and positioning the lower end of the leg or legs on the platform.

Another feature of the invention is that the same principles employed in the barge construction can be embodied in a relatively smaller and lighter well servicing barge with the same advantages of safety, mobility and economy.

As is well known, the drilling and servicing of wells in a high pressure zone is inherently dangerous because of the fire hazard involved. Heretofore, well drilling or servicing barges had to come into close contact and in an exact relationship with a platform associated with a well to be drilled or serviced. This requires very precise maneuvering of the barge which is always difficult and dangerous, particularly in unprotected water where dead calm conditions seldom obtain. Expensive fires have occurred in the past that have destroyed the platform installation as well as the drilling and servicing units because of the lack of a sufficient safety gap between the units and the well head. Some over water fires have raged unchecked for weeks despite all efforts to control them. Over-water oil or gas fires, in addition to creating a serious personnel hazard and equipment risk, also involve the risk of spreading flaming oil over the water endangering other installations.

The present well drilling and servicing barge and its method of use greatly reduces the fire hazard by making it possible to locate the well drilling and servicing units a safe distance from the well head. In addition, in a servicing operation it is possible to control the approach of the barge to the well platform from any angle. Once the barge has been maneuvered into the desired working position, it is raised to the desired level and the space between the barge and platform is then spanned by a combination bridge and working fioorlifted into place by the crane boom on the barge. The crane boom is 'then converted into a drilling or servicing derrick by adding one or more rigid legs thereto in a manner described more fully hereinafter.

Still another important feature is that the use of the present apparatus avoids the usual loss of time of the crew and equipment during bad weather conditions often experienced with conventional apparatus incidental to platform erection and well drilling and servicing operations.

Other features will be apparent from the following description and accompanying drawings, in which:

FIG. 1 is a side view showing the apparatus of the present invention set for a well drilling operation;

FIG. 2 is a right end view of the apparatus shown in FIG. 1;

FIG. 3 is a diagrammatic view of the barge as it appears when first towed to a selected well site;

FIG. 4 is a similar view showing the barge raised above the water;

FIG. 5 illustrates the first step in erecting a small platform over the water beyond one end of the barge;

FIG. 6 shows the platform supported by the barge while pilings for supporting the platform are being mounted in place;

FIG. 7 illustrates the step of positioning a combination bridge structure and derrick fioor across the gap between the barge and platform;

FIG. 8 illustrates the manner in which the crane boom is converted into a drilling derrick;

10-16 of FIG. 1;

FIG. .11 is a fragmentary sectional view showing certain details of the derrick legs which enable the same to be extended or collapsed;

FIG. 12 is a. fragmentary view illustrating the manner in which the lower ends of the derrick legs may be secured to the derrick floor;

FIG. 13 .is a fragmentary view showing the platform erected on the piling and the link connection between the barge and platform removed in preparation for a drilling operation;

FIG. 14 is a plan view of a well servicing barge and illustrates the manner in which the barge is maneuvered to make a safe approach to the well platform;

FIG. 15 shows the servicing barge raised and a combination bridge structure and working floor positioned across the gap between the barge and platform;

FIG. 16 is a diagrammatic side view of the barge illustrating the use of a single leg for supporting the crane boom; and

FIG. 17 is a right end view of the structure shown in FIG. 16.

It is to be understood that conventional equipment such as crews quarters, mud tanks, mud pumps, shale shakers, etc. required for a well drilling or servicing operation, have been omitted from the drawings in the interest of simplicity. Only those elements of the invention have been shown as are required for an understanding of the principles of construction of the apparatus and its method of use for over-water well drilling and/or well servicing operations.

Referring first to FIGS. 1 and 2, a barge that may be used for either a'well drilling or well servicing operation is identified by the numeral 1. The barge has a working deck 2 and the hull of the barge has a row of open- V a mounted in each opening 3 and is held in 'a raised position, as shown in FIG. 3 by a caisson jack 7 of'any known or suitable construction. The caisson jacks 7 may be actuated by equipment (not shown) contained on the J barge 1. The individual caissons 6 can be held raised by conventional clamps while the barge is in transit, instead of being held by the jacks 7.

After the barge 1 has been towed to the desired well location, the jacks 7 are operated to lower the cassons 6 into the water. As is well known, the jacks 7 include elements for successively gripping and releasing the caissons 6 in a manner to force the caissons downwardly, such action being reversible when it is desired to raise the caissons. If the bottom is soft, the jacks 7 are operated to cause the lower ends of the caissons 6 to penetrate the bottom until a firm footing is reached. The jacks 7 are further operated to raise the barge 1 relative to the caissons 6 until the barge is lifted to a desired height above the water. The caissons 6 are then locked against movement relative to the barge 1 by the jacks 7, or by clamping the caissons 6 to hold the barge raised for a given drilling or servicing operation.

The barge 1 carries a relatively small platform 10 on its deck 2 and the next step consists in mounting the platform It} on the barge, but spaced far enough from the barge to provide a safety space in case of fire. The platform 10 is shown beyond one end of the barge 1, but it could be positioned at either side. For this purpose, a conventional crane structure 11 is mounted on the deck 2. This structure includes a lower frame work 12 fastened to the deck 2 and a superstructure 13. The superstructure 13 can be rotated relative to the frame 12 through a conventional turntable 14. A crane boom also .be' understood that electrical current for operating the motors 3'4 and 50 is provided by a generator (not shown) driven from the drill rig engines (not shown).

A pair of spaced arms 51 extend from an end 52 of the barge 1. These are connected'to braces 51a also extending-from the barge. A pair of relatively short arms '54 extend from the platform and each carries a pin 55 adapted to be received in the notch 53. The platform "10 is lifted-by asling 25a (see FIG. 5) attached to the hook 25-, from the deck 2 of the barge 1 to a position e such that the pins 55 are received in the notches 5-3.

15 is pivotally connected to the superstructure 13 by a 7 pin 16. A conventional draw works 17 is mounted on the deck 2 within the frame work '12. The draw works includes a cable drum 18 and the usual engines 19' for driving the various components of the draw works. A sheave 20 is rotatably mounted upon a shaft 21 on the superstructure 13. A crown block 22 is carried by the boom 15 adjacent its outer end. A main cable or fast line 23 extends from the drum 18 over the sheave 20 to the crown block 22 and around a travelling block 24 as sociated with a hook 25. It will be understood that the drill stem (not shown) is supported by the hook 25 during a drilling operation.

One end of a cable 26 is secured to the boom 15 as indicated at 27. The opposite end of the cable 26 is secured to a link structure 28 associated with a sheave 29. Another sheave 30 is mounted upon a shaft 31 on V the superstructure 13. A boom topping line 32 extends around the sheaves 29 and 31 and is controlled by a drum 33. The drum 33 is driven in 'a conventional manner by a reversible electric motor 34. The drum 33 and motor 34 are enclosed by a housing 35.

A cable 36 extends from a drum 37 over a pulley 38 on the superstructure 13, then over a sheave 39' mounted on the opposite side of the boom 15 and then over a sheave 40 on the outer end of the boom 15 and then through a conventional sheave block 41 to an anchor 42. A rigging line 43 extends from the sheave block 41. A utility line 44 extends from a drum 45, over the sheave 39, then over a pulley '46 mounted on the lower side of the boom 15, through a pulley block 47 to an anchor 48. The pulley block 47 carries a hook 49 for lifting drill pipe, caisson or other equipment from the deck 2. The drum 37 controlling the cable 36 and the drum controlling the utility line 44 are driven by an electric motor--50, through conventional mechanism. It is to be understood that the electric motors and Share operated by remotecontrols (not shown) actuatable from the deck of the barge 2 or from any point convenient to the driller. It will The arms 51 serve to space the platform it? away from the hull of the barge 1 to provide a safety gap. 'The platform 10 is further temporarily mounted on the barge by means of uprights 56 and'links 57 connected at one end to the uprights and with the barge deck as indicated at 58. Additional links 59 are connected with the uprights 56 and with the platform 16 as indicated at 60. The links 59 are connected with the uprights 56 and with the platform 10 by conventional pins 61 and 62.

After the platform 10 has been mounted upon the barge 1, as described above, the sling 25a is removed and the cable 23 and hook 25 are utilized to successfully position pilings 63 in spaced openings 64. The openings 64 in the platform 10 thus serve as a template for lo eating the position of the pilings '63. The pilings 63 army be driven or jetted into position until they reach andderrick floor 67, which constitutes a drilling table,

from the deck 2 of the barge 1 into a position where it spans the gap between the end 52 of the barge and the platform 16. In actual practice this gap should be at least twenty (20) feet wide. The bridge structure 66 includes a frame work 68 of suitable design that rests upon the platform floor 65 and also upon the barge deck 2. A ramp 69 provides for easy access to the derrick floor 67 from the deck 2. The bridge structure 66 is heavy enough to remain fixed in the position in which it is placed. However, it can be secured against movement relative to the barge 1 and platform 10 by any suitable anchoring means.

A guard rail 70 extends substantially around the derrick floor 67. The derrick floor 67 has an opening in which a conventional rotary table 71 is mounted. This table is rotated to drive the drill stem, by mechanism (not shown) built into the bridge structure 66. The platform 10 (FIG. 1) has an opening 72 and the table 71 is directly above said opening. Well casing 72a is subsequently positioned in the opening 72. Blow-out preventer equipment (not shown) is also later installed between the platform 10 and the derrick floor 67.

The crane boom '15 has a pair of rigid derrick legs 73 pivotally connected thereto as indicated at 74, one leg being disposed on each side of the boom. During the erection of the platform 10 and the positioning of the bridge structure 66, the derrick legs 73 are fastened to the boom 15 and are suitably held in a retracted position, as indicated in FIGS. 3 to 7. The lower ends of the derrick legs 73 are then released and permitted to hang substantially vertically from their pivots 74. The boom 15 is then manipulated to position the legs 73 over the rotary table 71 so that the lower ends of the legs are disposed upon opposite sides of the rotary table, as will be apparent from FIGS. 2 and 10. The legs 73 each have a pin 75 at their lower end received in U-shaped brackets 76 welded to the derrick floor 67, as best illustrated in FIGS. 2 and 12. The pins 75 are retained in the brackets 76 by hooks 76a pivoteda-t 76b on said brackets. A toggle linkage 76c is connected with each hook 76a and is actuated by an air operated, quick-release device including a cylinder 76d, a piston 76e, and a rod 76 connected to the linkage 760. The cylinder 76d is pivoted at 76D to a U-shaped bracket 76E welded or otherwise secured to the deck 2. The supply and exhaust of air under pressure to the cylinder 76d is effected through pipes 76g and 76h by valve means (not shown) controlled from the barge 1. The quick-release device is provided for emergency purposes, as explained more fully hereinafter.

The boom 15 and the derrick legs 73 form a tripod. At the same time, the addition of the legs 73-to the boom 15 converts the same into -a well drilling-or servicing derrick. The legs 73 serve to maintain the boom 15 in a fixed position relative to the derrick floor and well and thereby maintain the crown block 22 and travelling block 24 in accurate vertical alignment with the rotary table 71, regardless of any slack or stretch in the boom topping lines 26 and 32. In order to secure proper initial alignment between the crown block 22 and the rotary table 71, the derrick legs 73 are made adjustable. Thus, each derrick leg 73 includes sections 77 and 78, FIG. 11, which partially overlap in telescoping relation. The sections 77 and 78 are preferably constructed from lengths of angle iron 79 and 80, respectively, riveted or welded together, and interconnected by horizontal angle members 81 and 82 and diagonal angle braces 83 and 84, respectively.

The section 77 has a plate 85 mounted therein and the section 78 has a similar plate 86 mounted therein. A cylinder 87 is disposed between the two plates. A piston 88 is mounted in the cylinder 87 and one end of a rod 89 is connected thereto. The lower end of the cylinder 87 is connected as indicated at 90 to the plate 86 and the piston rod 89 is pivotally connected as indicated at 91 to the plate 85. A pipe 92 is connected to the lower portion of the cylinder 87 for admitting and exhausting operating fluid from the cylinder below the piston 88. A similar pipe 93 is connected to the upper portion of the cylinder 87 for admitting and exhausting operating fluid from the cylinder below the piston 88. Thus, the cylinder 87, piston 88 and rod 89 function as a hydraulic jack for separating the sections 77 and 78 to extend the length of the derrick leg 73, or for effecting movement of the sections toward each other to shorten the overall length of the leg. The pipes 92 and 93 are connected with control valve means and fluid pressure source (not shown).

The boom 15 includes telescoping sections and a piston and cylinder construction like that embodied in the legs 73. The described structure provides a rigid derrick including a boom 15 and legs 73, all of variable iength. This makes it possible to adjust the length of the boom 15 and/or legs 73 so that the legs can assume a substantially vertical position above the well hole, thereby positioning the crown block 22 in vertical alignment with the axis of the rotary table 71. Should the legs become slightly tilted as a result of the barge or platform settling while in use, they can readily be restored to a true vertical position simply by adjusting the length of the boom 15 rather than adjusting the angle of the boom or the length of the legs 73. This arrangement also facilitates the handling of drill pipe, casing, etc. in subsequent operations. At the same time the derrick legs 73 transmit the major downward thrust of the drilling working load to the derrick floor 67 and to the platform while the boom 20 transmits the minor downward thrust of such load to the barge. The boom also opposes and cancels out the tendency of the cable 23 from the draw Works 17 to pull over the derrick legs 73.

While the hydraulic cylinder 87 will maintain the leg sections 77 and 78 in any desired position of adjustment,

it will be understood that any auxiliary bolting or damp ing means may be employed for the same purpose.

After the derrick legs 73 have been mounted in place, a fourble board 94, FIGS. 1 and 8, is mounted upon the derrick legs 73 at a suitable height above the derrick door 67. A suitable guard rail 95 is mounted upon the fourble board 94. Drill pipe or casing 96 may be stacked in the fourble board, as indicated in FIG. 1. It will be :understood, of course, that the deck 2 of the barge is adapted to serve as a storage space for any drill pipe, casing, etc. not in use, and suitable racks 97 are provided for this purpose. Such pipe or casing can be conveniently handled by the rigging line 43 or the utility line 44.

Normally, upon the successful completion of a well drilling operation, the derrick legs 73 will be released from the derrick door 67 by releasing the toggle linkage 76 and swung to their retracted position. The bridge structure 66 is then restored to the barge deck 2 and suitable oil well pumping or producing equipment 98 is installed upon the platform 10, as shown in FIG. '9. The barge 1 is then lowered by operating the jacks 7 and then moved away under its own power or by a tug boat 99.

As a precautionary measure, at the start of a drilling operation, the links 59 are disconnected from the platform 10 so that the pins form the only physical inter-connection between the platform 10 and the barge 1. In the event of fire, various expedients may be followed, depending upon the nature of the fire. For example, the toggle 76 can be released, thereby freeing the pins 75 so that the derrick legs 73 can be raised and swung to one side out of the path of the escaping gas and/or oil. This can be done by taking up on the boom topping line 32 and paying out the fast line 26 connected with the drill stem (not shown) to permit the necessary relative movement between the derrick legs 73 and the drill stem, if the stem happens to be connected to the travel block 24. All air and mud lines (not shown) can also be disconnected, if necessary. If advisable the jacks 7 may be operated to lower the barge 1 onto the water so that it can be pulled away with a minimum of damage. The notch 53 readily permits the barge to free itself from the platform pins 55 during this operation.

FIGS. 14 and 15 illustrate a well servicing barge 1a which obviously need not be as large nor as elaborately equipped as the drilling barge 1. However, the servicing barge 1a is provided with similar jacks 7a, caissons 61a, and a rotary crane structure 11a, including a boom 15a, and derrick legs 73a.

With reference to FIG. 14, and assuming that the oil well at the platform 10 requires servicing, the barge 1a is moved to a position in proximity to the platform 10, but a greater distance from the platform than the desired working distance. Anchors 100 and 101 are thrown overboard and with the lines 102 and 103 attached thereto are associated with suitable winches 104 and 105, respectively, mounted on the deck 2a of the barge 1a. The barge 1a can easily assume any random position within the working radius relative to the platform 10. This contrasts sharply with the risk involved in the indexing and the precise position required by present service barges relative to the well platform. The barge 1a is maneuvered into final position relative to the platform 10 under its own power or by a tug 106. The position of the barge 1a relative to the platform 10 is controlled at such time by paying out the lines 102 and 103 as required. The barge 1a is never permitted to contact the platform 10. In fact, the barge 1a is always kept distant from the platform 10 to provide a safety gap in the event of fire, and to minimize the danger of knocking the well platform over. After the barge 1a has been moved to within the working radius of the boom 15a, the caissons 6a are forced down by the jacks 7a to elevate the barge 1a above the water to the level of the platform 10. The anchor lines 102 and 103 are slacked off during the raising operation.

between the barge 1a and platform 1%.

The lower end of the derrick legs 73a can be released from the boom a and positioned upon the working floor 108, in the same manner described in connection with the derrick floor 67. Thus, the legs 73a cooperate with the boom 15a to providea rigid derrick structure for, servicing 1 the well at the platform.

'After the well servicing operation has been completed and the bridge 107 restored to the deck of the barge la, the jacks 7a are operated to lower the barge 1;: onto the water. Meanwhile, the slack in the lines 102a and 103a is taken up so that the position of the barge still remains under close control. After the barge 1a rests upon the water, the anchor lines are further taken up and the anchors raised while the tub 106 is pulling the barge 1a farther away fromtheplatformlt). The barge is then towed to the site of another well requiring servicing.

FIGS. 16 and 17 illustrate a modified construction adapted for use upon either awell drilling or well servicing barge. More specifically, the construction embodies a modification wherein a single derrick leg 7% is associated witha boom 15]) instead of the two derrick legs 73 and 73a previously referred to. As is shown in FIG. 16, the derrick leg 73b. is pivotally connected at 169 to the lower side of the derrick boom 15a and its lower end is shown resting upon the platform 10, although it will be understood that the same may rest upon aderrick floor such as the derrick floor 67 or upon a working fioor such as the floor 108, depending upon the operation to be performed.

In order to render a derrick of this type stable, cables 110 and 111 are connected with the boom 15b at one end as indicated at 112 and anchored to the barge 1b as indicated at 113. Obviously, the leg 73]) will transmit the major downward thrust of the load on the travel block 24b to the platform 1% while the boom 15] will transmit the minor thrust to the barge 1b.

It will be apparent from a study of the invention described herein, that:

The fire hazard is greatly reduced in both overwater well ,drilling and servicing operations-by isolating the .crews quarters, and principal equipment by a wide air gap from the constant danger point, namely the well head.

The ability to quickly erect a platform and start and carry onover-water drilling operations in any weather eliminates the crew and equipment down-time lost with prior equipment and methods of installation.

The ability to easily maneuver a service barge into safe working range of a platform froma random position in rough weather minimizes the hazard of collision with the platform.

The rotary crane provides great versatility since it is adapted to be used in positioning the caissons in the barge openings, erecting the platform, and installing the platform piling. The ability to readily convert the crane into 7 a rigid oil well drilling and/ or servicing derrick eliminates the necessity of a separate expensive unit for these functions.

It will be understood that various changes may be made in the details of construction and in the arrangement of the components of the various apparatus disclosed herein,

without departing from the prinicples of the invention or the scope of the annexed claims. Likewise, the sequence of steps described with respect to the method of erecting the platform 10, positioning the bridge structure 66 to 107, etc. may be varied to suit specific requirements.

I claim:

1.. In combination, a barge including well drilling and servicing means; means for maintaining said barge raised above water; an over-water well-producing platform spaced from an edge of said barge; means for supporting said platform above water, independently of said barge;

supporting leg includes means for adjusting its length.

3. In combination, a barge including well drilling and servicing means; means for maintaining said barge raised above water; an over-water well-producing platform spaced from an edge of said barge; means for supporting said platform above water, independently of said barge; a boom having its inner end pivotally connected with said barge; an upright leg pivotally connected at its upper end with the outer end of said boom and having its lower .end resting upon said platform, whereby the major downward thrust of any working load on said boom is transmitted to said platform through said upright legs; and means holding said boom in position to maintain said leg upright.

4. In combination, a barge including well drilling and servicing means; means for maintaining said barge raised above water; an over-water well-producing platform spaced from an edge of said barge; means for supporting said platform above water, independently of said barge; a derrick boom having its inner end pivotally connected with said barge; and a pair of generally upright legs pivotally connected at their upper end with the outer end of said boom and having their lower ends spaced apart and resting upon said platform, whereby the major downward thrust of any working load on said derrick boom is transmitted to said platform through said upright legs.

5. Over-water well drilling and servicing apparatus, comprising: a barge; means carried by said barge operable to raise said barge-to a desired height above the water; a relativelysmall platform spaced away from said barge; means independent of said barge for supporting said platform at a desired height above the water; a bridge structure extending across the space between said barge and platform and including a derrick floor provided with derrick drilling floor spanning the space between said barge and platform; a derrick boom having its inner end pivotally connected with said barge; and a pair of generally upright legs pivotally connected at their upper end with the outer end of said boom and having their lower ends spaced apart and resting upon said derrick floor directly above said platform, whereby the major downward thrust of any working load on said derrick boom is transmitted to. said derrick floor through said upright legs.

7. Well drilling and servicing apparatus, comprising: a well drilling and servicing barge including well drilling and servicing means; a rotatable crane structure mounted upon said barge, said crane structure including a sheave and a boom having a crown block; a draw works on said barge below said crane, having a fast line extending upwardly therefrom and approximately through the center of rotation of said crane structure, over said sheave, and then over said crown block; a relatively small well-producing platform located a substantial distance from an edge of said barge; means for supporting said platform above water independently of said barge; a removable bridge structure extending across the spacebetween said barge and platform and including a floor; and derrick legs removably arranged between said floor directly above said platform and the crown block end of said boom, and connected to the latter to transmit the major downward thrust of the drilling working load to said small platform through said bridge structure, said boom transmitting the minor downward thrust of the drilling working load to said barge and also opposing the tendency of the draw works to pull over the derrick legs.

8. The combination defined in claim 4, in which the platform has an opening for a well casing and the lower ends of the legs are positioned on opposite sides of said opening.

9. A drilling barge comprising: a buoyant body having a platform-like working deck; means carried by said body for selectively floating the latter or at least partially supporting the same on the marine bottom with said deck above water; a drilling table carried on said deck; a rotary mounted on said table; means mounting said table for movement between an inoperative position wherein said table does not project outboard of the peripheral outline of said body a distance appreciably greater than the thickness of said table and an operative position wherein said table is horizontal and said rotary is disposed outboard of said outline; a drilling derrick carried on said deck and having at least a tackle-suspending top portion positionable over and in vertical alignment with said rotary when said table is in said operative positon; a producing platform having a drilling openng extending therethrough, a support means on the body detachably engageable with said platform for releasably supporting the latter outboard of the outline and beneath the table in the operative position thereof with said opening in vertical alignment with the rotary, a plurality of marine-bottom-engageablelegs securable to said platform for supporting the latter independently of the body when said support means is detached from said platform, the support means including outwardly extending brackets on an edge of the body adapted to have one side of the platform rest thereon and inclined rods extending from said body to the opposite side of said platform and detachably connected thereto.

10. A drilling barge comprising: a buoyant body having a platform-like working deck; means carried by said body for selectively floating the latter or at least partially supporting the same on the marine bottom with said deck above water; a drilling table carried on said deck; a rotary mounted on said table; means mounting said table for movement between an inoperative position wherein said table does not project outboard of the peripheral outline of said body a distance appreciably greater than the thickness of said table and an operative position wherein said table is horizontal and said rotary is disposed outboard of said outline; and a drilling derrick carried on said deck and having at least a tackle-suspending top portion positionable over and in vertical alignment with said rotary when said table is in said operative position.

11. The method of drilling a marine well, the steps comprising: floating a drilling barge having a working deck to the drilling site; at least partially supporting the barge on the marine bottom with the deck above water; temporarily and releasably supporting a producing platform from, and outboard of, the barge; drilling a well in the marine bottom by operating downwardly through the platform; installing a plurality of marine-bottomengaged supporting legs for the platform and supporting the latter thereon; releasing the support of the platform from the barge; refloating the barge; and floating the barge away from the site.

12. A drilling barge comprising: a buoyant body having a platform-like working deck; means carried by said body for selectively floating the latter or at least partially supporting the same on the marine bottom with said deck above water; a drilling table movably carried on said deck in an inoperative position wherein said table does not project appreciably outboard of the peripheral 13. The structure defined in claim 12 wherein the selective means includes a plurality of marine-bottomengageable body-supporting legs extensible and retractable beneath the body and power-operated means for selectively effecting or restraining extension or retraction of said legs.

14. The structure defined in claim 12 in which the table-supporting means includes a producing platform having a drilling opening extending therethrough, and including support means mounted on the body for releasably supporting said platform in a horizontal position outboard of the outline beneath the operative position of the table and with said opening in vertical alignment with the operative position of the rotary.

15. The structure defined in claim 14 wherein the producing platform is provided with apertures for the reception of marine-bottom-engageable legs securable to said platform to support the latter independently of the body.

16. The structure defined in claim 12 in which the table-supporting means includes a producing platform having a drilling opening extending therethrough, and including support means on the body detachably engageable with said platform for releasably supporting the latter outboard of the outline and beneath the operative position of the table with said opening in vertical alignment with the operative position of the rotary, and a plurality of marine-bottom-engageable legs securable to said platform for supporting the latter independently of the body when said support means is detached from said platform.

17. The structure defined in claim 16 in which the support means includes outwardly extending brackets on an edge of the body adapted to have one side of the platform rest thereon and inclined rods extending from said body to the opposite side of said platform and detachably connected thereto.

18. A drilling barge comprising: a buoyant body having a working deck; means carried by said body for selectively floating the latter or at least partially supporting the same on the marine bottom with said deck above water; drilling equipment carried on said deck for operation outboard of the peripheral outline of said body; a producing platform having a drilling opening extending therethrough; means for temporarily and releasably supporting said platform from, and outboard of, said body, said drilling equipment including a drilling table provided with a rotary and movable between an inoperative position wherein said table does not project outboard of the outline a distance appreciably greater than the thickness of said table and an operative position wherein said table is horizontal and said rotary is above and in vertical alignment with said platform drilling opening; and a plurality of marine-bottom-engageable legs securable to said platform for supporting the latter independently of said temporary supporting means.

19. The structure defined in claim 18 in which the platform has a plurality of apertures extending therethrough for receiving and guiding the platform-supporting legs down into engagement with the marine bottom.

20. The method of drilling a marine well, the steps comprising: floating to the drilling site a drilling barge having a working deck and carrying all necessary equipment to drill or service a well; at least partially supporting the barge on the marine bottom with the working deck of the barge above water; supporting a producing platform adjacent to and outboard of the marine-bottomsupported barge; moving a drilling table having a rotary from an inoperative positionon the barge to an operativeposition over the platform wherein the table is at least partially supported on the barge; drilling a well in the marine bottom by operating downwardly from the table through the platform; moving the table back to its inoperative position; refloating the barge; and floating the barge away from the site leaving the producing platform in situ.

i 21. The method of servicing a marine well provided with a producing platform, the steps comprising: floating to a position adjacent the platform a drilling barge having a working deck and carrying all necessary equipment to drill or service a well; at least partially supportderrick carried on said deck and having at least a tacklesuspending top portion positionable over and in vertical alignment with said rotary when said table'is in said rel ing the barge on the marine bottom with the working deck of the barge above water and adjacent the platform and with the latter outboard of said barge; moving a drilling table having a rotary from an inoperative position on the barge to an-operative position over the platform with the rotary aligned with the well and at least a portion of the weight of the table supported on the barge; re-drilling or cleaning out the well by operating downwardly from the table; moving the table back to its inoperative position; refioating the barge; and floating the barge away from the platform.

22. A floating barge for subaqueous operations including means carried thereby for selectively floating said barge .or at least partially supporting the same on the marine bottom with its deck above water, a drilling derrick mounted on the barge and having atleast a top portion extensible outsiderof the peripheral outline of the barge, said barge having supporting means extending outwardly from one side thereof beneath said derrick top portion, a producing platform arranged to releasably rest on said supporting means, said producing platform having at least one vertical drill opening, a table movable to a horizontal operative position above said producing platform, said table having at least one vertical drill opening adapted to register with a drill opening in the producing platform when the table is in its operative position, said drill openings, when in registration, being arranged to receive a drilling tool supported by the derrick, means carried by said table for rotating the drilling tool, and means installable when said platform is resting on said supporting means for supporting said platform on the marine bottom independently of said barge.

23. A drilling barge comprising: a buoyant body having a platform-like working deck; means carried by said body for selectively floating the latter or at least partially supporting the same on the marine bottom with said deck above water; a drilling table provided with a rotary carried on said deck for movement between an inoperative position wherein said table does not project appreciably outboard of the peripheral outline of said body and an operative position wherein said table is horizontal and operative position; a producing platform having a drilling opening extending therethrough; support means on the body detachablyengageable with said platform for releasably supporting the latter outboard of the outline and beneath the operative position of said table with said opening in vertical alignment with the operative position of the rotary; and-a plurality of marine-bottomengageable legs securable to said platform for supporting the latter independently of the body when said support means is detached from said platform, the support means including outwardly extending brackets on an edge of the body adapted to have one side of the platform rest thereon and inclined rods extending from said body to the opposite side of said platform and detachably connected thereto. i a

24. The method of drilling a marine well the steps comprising: floating to the drilling site a drilling barge having a working deck carrying a drilling table in an inboard inoperative stowed position; at least partially supporting the barge on the marine bottom with the deck above water; releasably supporting a producing platform from, and outboard 'of the barge; installing a plurality of marine-bottom-engaged supporting legs for the plat-.

form and transferring the support of the latter from the 'barge to the legs; moving the drilling table into an operative position over the platform and at least partially supporting the table from the barge in the operative position; drilling a well in the marine bottom outboard of and in spaced relation to the barge by operating downwardly from the table through the platform; moving the table back to its stowed position on the barge; refloating the barge; and floating the barge with the table carried thereonaway from the site.

References Cited in the 'file of this patent UNITED STATES PATENTS 89,794 Rowland May 4, 1869 1,909,528 Gars'on May 16, 1933 1,917,053 Nelson et al. July 4, 1933 2,308,743 Bulkley et a1. Jan. 19, 1943 2,378,254 Swaney June 12, 1945 2,475,933 Woolslayer et al July 12, 1949 2,515,540 Willey et a1 July 18, 1950 2,603,068 Wilson July 15, 1952 2,628,818 Graham Feb. 17, 1953 2,653,796 McGee et al Sept. 29, 1953 FOREIGN PATENTS 600,129 Great Britain Apr. 1, 1948 

